There is a growing demand by industry, governmental regulatory agencies and consumers for durable and inexpensive products that are functionally comparable or superior to metal products. This is particularly true in the automotive industry. Developers and manufacturers of these products are concerned with the strength parameters, such as impact, bending, stretching, and twisting resilience. To meet these demands, a number of composite materials have been engineered. A relatively inexpensive product is GMT composite. GMT composites can be molded and stamped into a variety of suitable products, most notably are bumpers. Previous known GMT products do not have sufficient surface qualities to be used in visible applications on automobiles, such as body panels. The quality of finish suitable for painting is designated a Class-A surface. Currently, only sheet molded compounds (SMCs) are used on visible, painted automobile body components. SMCs are substantially more expensive than GMT fabricated parts, and generate a lot of scrap. What is needed is a GMT that has a Class-A surface that can be used in visible, painted parts. Furthermore, what is desired is a GMT composite that is impregnated with a low viscosity thermoplastic resin that has a latent polymerization catalyst, where in a B-stage process step, such as heated molding and stamping, the polymerization catalyst initiates conversion of the low viscosity thermoplastic resin to a polymerized material. The resulting composite should have the strength parameters, such as impact, bending, stretching, and twisting resilience, as well as the Class-A finish.
A review of the prior art follows: